Top of page bid (low range), in Google Ads, generally means the estimated lower end of bid amount needed to get your Ads on the top of the page, but at the lower end of estimated bid range.
100% of spend is limited by your max. bid limit refers to your Google Ad not being able to use all the budget allocation with the Maximum CPC bid limit being low. Reasons may be your competitor has outbid you for the keywords you are targeting, your quality score is low or your campaign optimization score.
Bid Setting Limited refers that your advertising campaign has been limited by bid limits that you have setup on your Ad’s bid strategy. It can be either related to daily budget or bidding strategy for example low Maximum CPC bid limit for example.
